DMV/F: https://msdn.microsoft.com/en-us/library/ms188068.aspx
SELECT c.session_id , c.auth_scheme , c.node_affinity , r.scheduler_id , s.login_name , db_name(r.database_id) AS database_name , CASE s.transaction_isolation_level WHEN 0 THEN 'Unspecified' WHEN 1 THEN 'Read Uncomitted' WHEN 2 THEN 'Read Committed' WHEN 3 THEN 'Repeatable' WHEN 4 THEN 'Serializable' WHEN 5 THEN 'Snapshot' END AS transaction_isolation_level , s.status AS SessionStatus , r.status AS RequestStatus , CASE WHEN r.sql_handle IS NULL THEN c.most_recent_sql_handle ELSE r.sql_handle END AS sql_handle , r.cpu_time , r.reads , r.writes , r.logical_reads , r.total_elapsed_time FROM sys.dm_exec_connections c INNER JOIN sys.dm_exec_sessions s ON c.session_id = s.session_id LEFT JOIN sys.dm_exec_requests r ON c.session_id = r.session_id